Streptococcal pharyngitis, streptococcal tonsillitis, or streptococcal sore throat (known colloquially as strep throat) is a type of pharyngitis caused by a group A streptococcal infection.[1] It affects the pharynx including the tonsils and possibly the larynx. Common symptoms include fever, sore throat, and enlarged lymph nodes. It is the cause of 37% of sore throats among children[2] and 5-15% in adults.[3]
Strep throat is a contagious infection, spread through close contact with an infected individual. A definitive diagnosis is made based on the results of a throat culture. However, this is not always needed as treatment may be decided based on symptoms. In highly likely or confirmed cases, antibiotics are useful to both prevent complications and speed recovery.[4]
The typical symptoms of streptococcal pharyngitis are a sore throat, fever of greater than 38 °C (100 °F), tonsillar exudates (pus on the tonsils), and large cervical lymph nodes.[4]
Other symptoms include: headache, nausea and vomiting, abdominal pain,[5] muscle pain,[6] or a scarlatiniform rash or palatal petechiae, the latter being an uncommon but highly specific finding.[4] The incubation period and thus the start of symptoms for strep throat is between one to three days post contact.[4] Strep throat is unlikely when any of the symptoms of red eyes, hoarseness, runny nose, or mouth ulcers are present. It is also unlikely when there is no fever.[3]
trep throat is caused by group A beta-hemolytic streptococcus (GAS).[7] Other bacteria such as non–group A beta-hemolytic streptococci and fusobacterium may also cause pharyngitis.[4][6] It is spread by direct, close contact with an infected person and thus crowding as may be found in the military and schools increases the rate of transmission.[6][8] It has been found that dried bacteria in dust are not infectious, although moist bacteria on toothbrushes or similar items can persist for up to fifteen days.[6] Rarely, contaminated food can result in outbreaks.[6] Of children with no signs or symptoms 12% carry GAS in their pharynx[2] and after treatment approximately 15% remain carriers.[9]
Untreated streptococcal pharyngitis usually resolves within a few days.[4] Treatment with antibiotics shortens the duration of the acute illness by about 16 hours.[4] The primary reason for treatment with antibiotics is to reduce the risk of complications such as rheumatic fever and retropharyngeal abscesses[4] and they are effective if given within 9 days of the onset of symptoms.[7]
The symptoms of strep throat usually improve irrespective of treatment within three to five days.[11] Treatment with antibiotics reduces the risk of complications and transmission; children may return to school 24 hours after antibiotics are administered.[4] The risk of complications in adults is low.[3] In children acute rheumatic fever is rare in most of the developed world. It is however the leading cause of acquired heart disease in India, sub-Saharan Africa and some parts of Australia.[3]
Complications arising from streptococcal throat infections include:
Acute rheumatic fever[5]
Scarlet fever[24]
Streptococcal toxic shock syndrome[24][25]
Glomerulonephritis[26]
PANDAS syndrome[26]
Peritonsillar abscess[3]
Cervical lymphadenitis[3]
Mastoiditis[3]
The economic cost of the disease in the United States in children is ~$350 million.
http://en.wikipedia.org/wiki/Streptococcal_pharyngitis